mutron III spotted

at a local guitar shop, tag says $275 i asked to play it but he said it didn't sound quite right. somthing wrong with the battery connectors(?) or somthing. i wanna try to get it for like $175 cuz it dosn't work is this a good idea or a bad idea to try and haggle so low and yet still pay that much for somthing that isnt in full working condition?